摘要
采用一步硬模板法炭化酚醛树脂和葡萄糖酸镁制备得到具有大表面积和层次化结构的微孔-中孔炭材料(HMMC)。在炭化过程中,葡萄糖酸镁分解形成纳米氧化镁(MgO)可以作为硬模板。制备得到的HMMC具有高的比表面积(1560m^2·g^(-1)),大的孔容(2.6cm^3·g^(-1)),可以实现较高硫的负载量,并可以提供硫体积膨胀的空间。此外,相互连通的孔结构和炭骨架也能够提供快速的电子和锂离子的传输通道。因此,与硫复合后得到的碳-硫杂化材料(HMMC-S)在0.3C电流密度下,初始放电容量高达939mAh·g^(-1),经150周循环后容量仍有731mAh·g^(-1),每周的容量损失率仅为0.15%。在较高的电流密度2C下,其容量仍可达626mAh·g^(-1),表现出优异的倍率性能和长循环稳定性。
Porous carbon materials can increase the conductivity of sulfur and restrain the shuttling of polysulfides in the electro-lyte. A hierarchical microporous-mesoporous carbon （HMMC） with a large surface area and pore volume was prepared by the sim-ple one-step carbonization of a mixture of magnesium gluconate （MG） and phenolic resin. The MG was transformed into nanosize magnesium oxide that acted as a hard template during carbonization to create mesopores. The HMMC has a high surface area （-1 560 m2·g-1） and large pore volume （-2. 6 cm3·g-1）,which provides abundant space for sulfur loading and accommodates volume changes during charge/discharge. The interconnected pore structure and carbon framework ensure fast electron and Li ion transfer. As the cathode of a Li-S battery the sulfur-loaded HMMC has a high discharge capacity of 939 mAh·g-1 at 0. 3 C and a re-versible capacity of 731 mAh·g-1 after 150 cycles with only a 0.15% capacity fade per cycle. Even at a high rate of 2 C,it still de-livers a high discharge capacity of 626 mAh·g-1,showing an excellent rate performance.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2017年第4期289-296,共8页
New Carbon Materials
基金
National Key Basic Research Program of China(2014CB932400)
National Natural Science Foundation of China(U1401243)
Shenzhen Basic Research Project(JCYJ20150529164918734,JCYJ20150331151358140,JCYJ20150331151358136)~~
关键词
微孔-中孔炭
大的孔容
层次孔结构
锂硫电池
Microporous-mesoporous carbon
Large pore volume
Hierarchical pore structure
Lithium sulfur battery
